Fatigue is common in primary Sjögren`s syndrome (pSS), but what leads to that fatigue is not fully understood. They hypothesized that there is a genetic basis for fatigue, and that specific gene-variants influence the severity of fatigue.

To investigate this further they performed a genome wide association study of 367 Scandinavian pSS patients.

They identified genetic variants in RTP4 exceeding the GWS level for association with fatigue. This gene encodes a protein involved in pain processing. Pain is known to influence fatigue, and this finding could point to a possible molecular explanation. ​​​​​​​

The present study is the largest GWAS of fatigue in autoimmune disease, and adds further evidence to a genetic regulation of fatigue.